Category : Unprotects for Games and Such
Archive   : CENT-UNP.ZIP
Filename : CENTURIO.UNP

 
Output of file : CENTURIO.UNP contained in archive : CENT-UNP.ZIP
Unprotect for Centurion


Tired of looking up protection codes for that expensive program you just
bought. Well we can do something about this nasty protection scheme.

For Norton users search the file OVL0.OVL for the byte pattern 5B 0B C0 74 06
and change the 74 to EB.

DEBUG users follow the steps below. It is assumed the DEBUG is in the path or
current dir.

1. DEBUG OVL0.OVL

2. At the DEBUG '-' prompt type E 616 EB to change the 74 to EB (JZ to JMP)

3. At the DEBUG '-' prompt type W to write the unprotected file

4. Type Q to quit

Okay, that's it. Just hit {Enter} when asked for the name of a place on
the map. For those interested the program change looks like this.

Before

XXXX:060E 50 PUSH AX
XXXX:060F E890EB CALL F1A2
XXXX:0612 5B POP BX
XXXX:0613 5B POP BX
XXXX:0614 0BC0 OR AX,AX ;AX will equal FFFF if you are wrong
XXXX:0616 7406 JZ 061E ;will jump if you are right
XXXX:0618 FF46FE INC WORD PTR [BP-02] ;increase counter for tries
XXXX:061B E97FFF JMP 059D ;jump back to start
XXXX:061E C746F4FFFF MOV WORD PTR [BP-0C],FFFF ;jumps here if you
XXXX:0623 2BF6 SUB SI,SI ; are right
XXXX:0625 EB06 JMP 062D ;jumps on
XXXX:0627 80B4446447 XOR BYTE PTR [SI+6444],47
XXXX:062C 46 INC SI
XXXX:062D B84464 MOV AX,6444

After

XXXX:060E 50 PUSH AX
XXXX:060F E890EB CALL F1A2
XXXX:0612 5B POP BX
XXXX:0613 5B POP BX
XXXX:0614 0BC0 OR AX,AX
XXXX:0616 EB06 JMP 061E ;ignore answer
XXXX:0618 FF46FE INC WORD PTR [BP-02] ; and skip this
XXXX:061B E97FFF JMP 059D
XXXX:061E C746F4FFFF MOV WORD PTR [BP-0C],FFFF ;you are right
XXXX:0623 2BF6 SUB SI,SI
XXXX:0625 EB06 JMP 062D ;jumps on
XXXX:0627 80B4446447 XOR BYTE PTR [SI+6444],47
XXXX:062C 46 INC SI
XXXX:062D B84464 MOV AX,6444


Courtesy of Bad Bob


  3 Responses to “Category : Unprotects for Games and Such
Archive   : CENT-UNP.ZIP
Filename : CENTURIO.UNP

  1. Very nice! Thank you for this wonderful archive. I wonder why I found it only now. Long live the BBS file archives!

  2. This is so awesome! 😀 I’d be cool if you could download an entire archive of this at once, though.

  3. But one thing that puzzles me is the “mtswslnkmcjklsdlsbdmMICROSOFT” string. There is an article about it here. It is definitely worth a read: http://www.os2museum.com/wp/mtswslnk/